Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Hood blanket... literally? (engine compartment thermal insulation)

user removed · 10-21-2009, 11:09 PM

04-09 Prius had a thermos to hold hot water for quick warm ups on restarts.

Saw one from a damaged car at my friends body shop. $1000 in parts to replace it. Held a decent amount of heat for 4 days in freezing temps.

Heat retention in the winter as well as preheating the coolant before initial starts would go a long way to achieving summertime mileage in wintertime.

There are other factors such as higher atmospheric density that cause winter temperatures to reduce mileage, but a significant amount of the difference could be eliminated if you could duplicate summertime conditions as far as fast warm ups, higher engine compartment temperatures and hotter coolant coming out of the radiator to the engine.

Also warmer air is a duplication of summertime temperatures and increases mileage, especially when compared to extreme cold temperatures experienced in northern climates.

All of these modifications in total have the same effect as normal summertime operating temperatures. Coolant exiting the radiator in summer is close to 120degrees fahrenheit compared to 60 degrees in wintertime, even lower when temps go lower than freezing.

We all know that with winter coming we will see a significant drop in mileage, at least for those who have significantly colder winters.

I used to do a quick check for radiator effectiveness by simply holding my hand on the top and bottom hoses. At 180 degrees I could hold my hand on the top hose for about 5 seconds. In winter the bottom hose was always much colder than the top hose as long as the radiator was doing it's job.

Remember, every cooling system is designed to handle the most extreme of situations, 100 degrees pulling a load up a steep incline, with the Ac blasting away which in many cars preheats the air before it gets to the radiator itself.

In arctic climates I would be it would be possible to hypermile a car with the radiator completely disconnected using only the heater core to keep the engine cool.

I always like the idea of a thermostat that was in the return circuit that mixed bypassed (uncooled) coolant with coolant going through the radiator to maintain the 120 degree temperature of the coolant entering the engine.

This would mean automatic ambient temperature compensation regardless of outside temperatures.

regards
Mech

10-21-2009, 11:09 PM	#84 (permalink)
user removed Master EcoModder Join Date: Sep 2009 Posts: 5,927 Thanks: 877 Thanked 2,024 Times in 1,304 Posts	04-09 Prius had a thermos to hold hot water for quick warm ups on restarts. Saw one from a damaged car at my friends body shop. $1000 in parts to replace it. Held a decent amount of heat for 4 days in freezing temps. Heat retention in the winter as well as preheating the coolant before initial starts would go a long way to achieving summertime mileage in wintertime. There are other factors such as higher atmospheric density that cause winter temperatures to reduce mileage, but a significant amount of the difference could be eliminated if you could duplicate summertime conditions as far as fast warm ups, higher engine compartment temperatures and hotter coolant coming out of the radiator to the engine. Also warmer air is a duplication of summertime temperatures and increases mileage, especially when compared to extreme cold temperatures experienced in northern climates. All of these modifications in total have the same effect as normal summertime operating temperatures. Coolant exiting the radiator in summer is close to 120degrees fahrenheit compared to 60 degrees in wintertime, even lower when temps go lower than freezing. We all know that with winter coming we will see a significant drop in mileage, at least for those who have significantly colder winters. I used to do a quick check for radiator effectiveness by simply holding my hand on the top and bottom hoses. At 180 degrees I could hold my hand on the top hose for about 5 seconds. In winter the bottom hose was always much colder than the top hose as long as the radiator was doing it's job. Remember, every cooling system is designed to handle the most extreme of situations, 100 degrees pulling a load up a steep incline, with the Ac blasting away which in many cars preheats the air before it gets to the radiator itself. In arctic climates I would be it would be possible to hypermile a car with the radiator completely disconnected using only the heater core to keep the engine cool. I always like the idea of a thermostat that was in the return circuit that mixed bypassed (uncooled) coolant with coolant going through the radiator to maintain the 120 degree temperature of the coolant entering the engine. This would mean automatic ambient temperature compensation regardless of outside temperatures. regards Mech